When an entrant vehicle enters or re-enters an atmosphere adjacent to a surface of a planet or satellite body, the atmospheric density at the entrant vehicle surface abruptly increases from substantially zero (≈1 particle/cm3) to a value at least millions of times as large in a very short time interval, of the order of a few seconds for a vehicle that enters or re-enters at velocities of the order of 10,000-30,000 kilometers per hour. This transition causes an abrupt and sustained increase in heating at and adjacent to surfaces exposed to the atmosphere, and the associated surface temperatures can exceed 3000° F. for an extended period.
What is needed is a heat shield for an entrant vehicle that can withstand the anticipated surface temperatures and that can be adapted to correspond to different entrant configurations of the vehicle (entrant velocity, entrant angle, atmosphere density distribution, etc.)